Laurie Barclay, MD

April 25, 2008

April 25, 2008 — Laparoscopic surgery was linked to a 50% reduction in hospital-acquired infection rates and a 65% reduction in hospital readmissions vs open surgery, according to the results of a retrospective analysis presented recently at the Society of American Gastrointestinal and Endoscopic Surgeons 2008 Annual Scientific Session and published in the April issue of Surgical Endoscopy. This analysis was limited to patients undergoing cholecystectomy, appendectomy, or hysterectomy.

"These results, combined with previous research into this area, strongly suggest [that] the benefits of laparoscopic surgery may apply to procedures beyond the 3 types included in this particular study to reduce the estimated 100,000 deaths associated with the 1.7 million hospital-acquired infections that occur annually in the [United States]," presenter and lead author Andrew I. Brill told Medscape General Surgery. Dr. Brill is director of minimally invasive gynecology at the California Pacific Medical Center in San Francisco.

"Additionally, this study is the first to examine infections specific to these procedures 30 days postdischarge," Dr. Brill said. "The study discovered that 40% of the infections identified occurred within 30 days after hospital discharge. Previous studies on postdischarge infections have been very limited, and it is likely that comparisons of laparoscopic and open surgeries have underestimated risks."

The investigators retrospectively analyzed data from 11,662 surgical admissions to 22 hospitals that used the nosocomial infection marker (NIM) to identify nosocomial infections occurring during hospitalization and postdischarge.

NIM is a computer algorithm that identifies the existence of nosocomial infections at the microbiological level, distinguishing likely pathogens from contaminants, identifying duplicate isolates, and temporally determining hospital- vs community-acquired pathogen acquisition. A previous multihospital study showed 86% sensitivity and 98.5% specificity of the NIM algorithm for detecting nosocomial infections.

In the present study, admission was for laparoscopic or open cholecystectomy in 32.7% of patients, for appendectomy in 24.0%, and for hysterectomy in 43.3%. Data were analyzed by source of infection, including urinary tract, wounds, respiratory tract, bloodstream, and others. The effect of certain potentially confounding variables, such as sex, age, insurance type, complexity of admission, admission through the emergency department, and hospital case mix index, was examined with single and multivariable logistic regression analyses.

Overall infection rates were 4.09% for open surgery and 2.11% for laparoscopic procedures. In analyses based on 399 NIMs identified in 337 patients, laparoscopic cholecystectomy and hysterectomy were each associated with a greater than 50% reduction in the overall odds of acquiring nosocomial infections compared with open surgery (66% reduction for laparoscopic vs open cholecystectomy; 52% reduction for laparoscopic vs open hysterectomy; P < .01 for each).

Laparoscopic and open appendectomy were not significantly different in terms of the odds of acquiring nosocomial infections.

Across hysterectomies, cholecystectomies, and appendectomies, laparoscopic surgery vs open surgery was associated with a reduction in the overall odds ratio (OR) for each type of nosocomial infection: an 80% reduction in the OR for respiratory tract infection, a 69% reduction in the OR for bloodstream infection, a 59% reduction in the OR for wound infection, a 39% reduction in the OR for urinary tract infection, and a 48% reduction in the OR for other types of nosocomial infections.

"A call to action must be heard to decrease open hysterectomy techniques, which have an increased nosocomial infection risk," said Steven D. McCarus, MD, chief of gynecological surgery and director of the Center for Pelvic Health at Florida Hospital Celebration in Orlando. Dr. McCarus was not involved with this study but was asked to provide independent commentary for Medscape General Surgery.

"Gynecologists and general surgeons will continue minimally invasive approaches to improve patient outcomes," Dr. McCarus said. "This paper especially endorses and emphasizes the benefits of minimally invasive surgery in the female patient."

Although 27% of patients found to have a nosocomial infection after discharge were readmitted to the hospital, laparoscopic cholecystectomy and hysterectomy were associated with a 65% reduction in readmissions for infections compared with open surgery (P < .01).

"By reducing the rate of infection, laparoscopic surgery has the potential to dramatically cut into the billions of dollars [in costs] incurred by the healthcare system due to hospital-acquired infections," Dr. Brill said. "The study also showed a 65% reduction in hospital readmissions for hospital-acquired infections when a patient underwent laparoscopic gallbladder removal and hysterectomy when compared to open surgery. This translates into cost savings for hospitals and payors."

Limitations of this study include absence of certain data that could potentially confound the results, such as antibiotic use, anesthesia scores, wound class, body mass index, prior hospitalization, and comorbidities of cardiovascular disease, diabetes mellitus, and immunodeficiency.

"There were definitely variables that were not considered in the model, including no adjustments for comorbid conditions, the severity of disease, and the intrinsic limits of present [diagnosis-related groups]," Dr. Brill said. "However, the statistical noise in this analysis is well balanced by the very large sample size, the use of all data during the time frame without any exclusions, and the fact that univariate and multivariate findings were consistent."

In terms of study weaknesses, Dr. McCarus agreed that the controls were limited by the absence of certain data and that there was no adjustment for patient comorbidities. However, a major strength was analysis of more than 11,000 admissions to 22 hospitals.

"Analysis of data was appropriately done, and conclusions were significant in comparing laparoscopic cholecystectomy and hysterectomy to their open counterparts," Dr. McCarus said. "Certainly this paper is an important one because of the associated nosocomial infection problem that is global. This encourages us as surgeons to continue additional research where we can address infection rates and risks."

In addition to potential reduction in nosocomial infections, laparoscopic surgery may confer other benefits over open surgery. However, potential harms should also be considered when choosing between these approaches.

"Whereas laparoscopic surgery carries the irreducible but small risk of injury to intraabdominal visceral and vascular structures, compared to laparotomy it provides superior cosmesis, more rapid recovery, less postoperative pain, and the option for outpatient surgery," Dr. Brill said.

"In untrained hands, laparoscopy has associated risks," Dr. McCarus agreed. "Laparoscopic surgery has benefits when performed by properly trained surgeons. A commitment on the part of the surgeon to learn and relearn minimally invasive techniques as technologies improve or change is paramount in reaching our endpoint — the endpoint being quicker recovery, decreased hospital stays, and faster [postoperative] recovery."

In terms of additional research, Dr. Brill recommends extending this research to other types of surgical procedures now routinely performed by both laparotomic and laparoscopic methods, such as colectomy. He also suggests investigating the comparative cost components of conventional vs laparoscopic surgery, keeping in mind the high costs related to nosocomial infections.

"This type of retrospective study utilizing data mining provides access to much more information than is available in other types of studies, making these studies integral in measuring the real-world impact of newer treatments and helping to determine the best and most efficient care for patients who need surgery," Dr. Brill concluded.

Ethicon Endo-Surgery, a Johnson & Johnson company that develops and markets advanced medical devices for minimally invasive and open surgical procedures, supported this study. Dr. Brill and Dr. McCarus are both consultants to Ethicon Endo-Surgery Inc.

Society of American Gastrointestinal and Endoscopic Surgeons 2008 Annual Scientific Session and Postgraduate Course. Presented April 12, 2008.

Surg Endosc. 2008;22:1112-1118.

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